Less than 80% of absorbed iron is promptly incorporated into erythrocytes of infants

Erythrocyte incorporation of an administered iron isotope has been used as a surrogate for iron retention on the assumption (validated in normal and iron-deficient adults) that 80-100% of the retained isotope is promptly incorporated into circulating erythrocytes. This assumption has not been validated in infants or children. The purpose of our study was to determine concurrently in normal infants absorption and erythrocyte incorporation of the stable isotope, (58)Fe. In a preliminary study (Study 1), we demonstrated that fecal excretion of ingested isotope occurs predominantly during the first 4 d after administration but continues beyond 7 d after ingestion, that is, beyond the point at which isotope in feces can be explained either by excretion of isotope that failed to enter enterocytes or by exfoliation of isotope-enriched enterocytes. In Study 2, we administered (58)Fe to nine younger (age 20-69 d) and nine older (age 165-215 d) term infants and collected feces for 11 d. Geometric mean retention of (58)Fe by the younger infants was 31.2% of intake at 4 d and 26.9% at 11 d, and by the older infants, 35.0% at 4 d and 32.5% at 11 d. Erythrocyte incorporation of (58)Fe 14 d after ingestion was 5.2% of the dose by the younger infants and 12.5% by the older infants. Utilization of retained (11 d) isotope thus was 19.8% by the younger infants and 38.3% by the older infants. We conclude that far less than 80% of retained isotope is promptly incorporated into erythrocytes (utilized) by infants.     

锌酞菁脂质体光动力作用引起小鼠肿瘤的细胞程序性死亡

电镜观察了锌酞菁脂质体光动力作用引起小鼠ＭＳ－２纤维肉瘤的形态学变化。发现其作用很强，并对肿瘤细胞有明显的直接影响。肿瘤细胞的结构表现出明显的程序性细胞死亡（ａｐｏｐｔｏｓｉｓ，ｐｒｏｇｒａｍｍｅｄｃｅｌｄｅａｔｈ）的特点：胞核染色质凝聚边集、核固缩、核破裂、染色质凝块流失、胞质内吞噬现象、胞膜表面肿胀粗钝的胞突形成、细胞碎裂等。加深了对锌酞菁脂质体光敏作用机理的认识，但其详细的发生机制和调节途径有待阐明。     

Human acute leukemia cell line with the t(4;11) chromosomal rearrangement exhibits B lineage and monocytic characteristics

A cell line, designated RS4;11, was established from the bone marrow of a patient in relapse with an acute leukemia that was characterized by the t(4;11) chromosomal abnormality. The cell line and the patient's fresh leukemic cells both had the t(4;11)(q21;q23) and an isochromosome for the long arm of No. 7. Morphologically, all cells were lymphoid in appearance. Ultrastructurally and cytochemically, approximately 30% of the cells possessed myeloid features. The cells were strongly positive for terminal deoxynucleotidyl transferase. They were HLA-DR positive and expressed surface antigens characteristic for B lineage cells, including those detected by anti-B4, BA-1, BA-2, and PI153/3. Immunoglobulin gene analysis revealed rearrangements of the heavy chain and kappa chain genes. The cells lacked the common acute lymphoblastic leukemia antigen and antigenic markers characteristic of T lineage cells. The cells reacted with the myeloid antibody 1G10 but not with other myeloid monoclonal antibodies. Treatment with 12-O-tetradecanoyl- phorbol-13-acetate induced a monocyte-like phenotype demonstrated by cytochemical, functional, immunologic, and electron microscopic studies. The expression of markers of both early lymphoid and early myeloid cells represents an unusual phenotype and suggests that RS4;11 represents a cell with dual lineage capabilities. To our knowledge, RS4;11 is the first cell line established from t(4;11)-associated acute leukemia.     

Computer graphics for digitally formatted images

The increasing use of digitally formatted imaging systems requires high-quality interactive gray-scale computer raster graphics systems for the management, display, and analog film recording of digital image and alphanumeric information. These systems are a combination of computer hardware and software and implement a set of graphics protocols. This paper describes a set of interactive graphics protocols that has been developed for clinical use.     

MR imaging of facial nerve enhancement in Bell palsy or after temporal bone surgery

The authors evaluated magnetic resonance (MR) images obtained with intravenously administered gadolinium in ten patients who had facial paralysis and no facial nerve tumor. In patients with either Bell palsy (four patients) or facial paralysis after temporal bone surgery (six patients), intratemporal facial nerve enhancement was seen. Facial nerve enhancement on MR images proved to be a nonspecific finding.     

Inhibition of endotoxin-induced activation of the coagulation and fibrinolytic pathways using a recombinant endotoxin-binding protein (rBPI23)

A recombinant endotoxin-neutralizing protein, rBPI23, was shown to partially prevent endotoxin-induced activation of the fibrinolytic and coagulation systems in experimental endotoxemia in humans. In a placebo- controlled, blinded crossover study, eight volunteers were challenged twice with an intravenous bolus injection of endotoxin (40 EU/kg of body weight) and concurrently received either rBPI23 (1 mg/kg) or placebo (human serum albumin, 0.2 mg/kg). rBPI23 treatment significantly lowered the endotoxin-induced fibrinolytic response, ie, reduced the release of tissue-type plasminogen activator, urokinase- type plasminogen activator, plasminogen activator inhibitor antigen, and complex formation of plasmin alpha 2-antiplasmin (P = .0078 for each). Plasminogen activator inhibitor activity was also reduced, but not significantly according to the Hochberg method (P = .0304). The endotoxin-induced activation of the procoagulant state as reflected by increase in F1 + 2 fragments and TAT complexes was blunted by rBPI23 infusion (P = .0391 [not significant according to the Hochberg method] and .0078, respectively). These results indicate that rBPI23 is capable of reducing both the activation of the fibrinolytic and the coagulation systems after low-dose endotoxin infusion in humans.